Friday, August 15, 2008 | Reason : In the News | print version

Big-brained Animals Evolve Faster

by Science Daily

Thanks to GP for the link.

http://www.sciencedaily.com/releases/2008/08/080814210006.htm

Big-brained Animals Evolve Faster

Ever since Darwin, evolutionary biologists have wondered why some lineages have diversified more than others. A classical explanation is that a higher rate of diversification reflects increased ecological opportunities that led to a rapid adaptive radiation of a clade.

A textbook example is Darwin finches from Galapagos, whose ancestor colonized a competitors-free archipelago and rapidly radiated in 13 species, each one adapted to use the food resources in a different way. This and other examples have led some to think that the progenitors of the major evolutionary radiations are those that happened to be in the right place and at the right time to take advantage of ecological opportunities.

However, is it possible that biological diversification not only depends on the properties of the environment an ancestral species finds itself in, but also on the features of the species itself? Now a study supports this possibility, suggesting that possessing a large brain might have facilitated the evolutionary diversification of some avian lineages.

Over 20 years ago, Jeff Wyles, Allan Wilson, and Joseph Kunkel proposed that big brains might favor adaptive evolutionary diversification in animals by facilitating the behavioral changes needed to use new resources or environments, a theory known as the behavioral drive hypothesis. When these authors formulated their hypothesis, evidence that the size of the brain limits the cognitive capacity of animals were scanty.

Since then, however, a substantial body of evidence has confirmed that animals with larger brains, relative to their body size, have more developed skills for changing their behavior through learning and innovation, facilitating the invasion of novel environments and the use of novel resources. Despite the progress, the role of the brain in the adaptive diversification of animals has remained controversial, mostly due to the difficulties to demonstrate that big-brained animals evolve faster.

Now, ecologist Daniel Sol of CREAF-Autonomous University of Barcelona and evolutionary biologist Trevor Price of the University of Chicago, provide evidence for such a role in birds in an article in The American Naturalist. Analyzing body size measures of 7,209 species (representing 75% of all avian species), they found that avian families that have experienced the greatest diversification in body size tend to be those with brains larger than expected for their body size.

These include the Picidae (woodpeckers), Bucerotidae (hornbills), Psittacidae (parrots), Strigidae (owls), Menuridae (lyrebirds) and Corvidae (crows). Brain size can promote morphological diversification because it facilitates range expansions and speciation, yet the analyses indicate that the brain-diversification association is statistically independent of geographic range and species richness.

"The most likely alternative," Daniel Sol states, "is that big brains enhance the rate of evolutionary diversification by facilitating changes in behavior, which would place new selection pressures on populations and favor adaptive divergence." Thus, in species with high cognitive styles, behavior might be, along with environmental factors, a major driving force for evolution.

Add to del.icio.us Posted: Friday, August 15, 2008 | Permalink

Comments 151 - 200 of 232 |

Reload Comments | Back to Top | Page Numbers

151. Comment #231282 by Brian English on August 16, 2008 at 5:06 am

Bonzai, correct again. The idea that we can randomize a sample and then claim it be representative of a population and our significant result be generalizable to that population seems to me to be a bit unjustifiable.

But I want to finish my degree so I don't argue that point too much. :)

Other Comments by Brian English

152. Comment #231284 by Laurie Fraser on August 16, 2008 at 5:10 am

This is a GOOD discussion. Should we invite isthatclear in?

Edit: hang on, Brian - just going to have a bit of a read up on the Treatise. I'll get back - you make an interesting and valuable point.

Other Comments by Laurie Fraser

153. Comment #231285 by Brian English on August 16, 2008 at 5:10 am

Why not Laurie. He can't be any less knowledgeable than I. :)

Other Comments by Brian English

154. Comment #231286 by Laurie Fraser on August 16, 2008 at 5:17 am

Jeez, you're into a bit of self-flagellation tonight, Brian - I would have said, after reading your posts here, that there's a mighty fine brain at work. You probably need BEER, my man - and plenty of it! :)

Other Comments by Laurie Fraser

155. Comment #231288 by 8teist on August 16, 2008 at 5:20 am

jeepers, Tyson homosexual has been knocked out of the 100m in the semifinals

Other Comments by 8teist

156. Comment #231290 by Bonzai on August 16, 2008 at 5:22 am

Brian,

Are you a psy major? Here is a book you may find interesting. I have the book but haven't got the time to read it though. It is a historical look at the development of statistical tools in psychology with a lot of interesting information.

http://books.google.com/books?hl=en&id=8pRuRm6WAp8C&dq=statistics

Other Comments by Bonzai

157. Comment #231291 by Bonzai on August 16, 2008 at 5:25 am

8theist

Tyson homosexual has been knocked out of the 100m in the semifinals

Excuse me?

Other Comments by Bonzai

158. Comment #231292 by 8teist on August 16, 2008 at 5:26 am

the olympics :)

.http://blog.washingtonpost.com/sleuth/2008/07/christian_sites_ban_on_g_word.html

Other Comments by 8teist

159. Comment #231293 by Bonzai on August 16, 2008 at 5:28 am

I know it is the Olympics. But what does homosexuality have to do with it.. Some of us here, are, ahem.. homosexuals.

Those are funny looking birds in your avatar.

Other Comments by Bonzai

160. Comment #231294 by 8teist on August 16, 2008 at 5:30 am

Bonzai , check the link .

thats what I was refering to :)

B , Darwins Finches I think

Other Comments by 8teist

161. Comment #231295 by Laurie Fraser on August 16, 2008 at 5:30 am

Tyson happy-person knocked out, 8? I'll have to stop reading the Treatise and turn on the telly.

Other Comments by Laurie Fraser

162. Comment #231296 by Brian English on August 16, 2008 at 5:34 am

Jeez, you're into a bit of self-flagellation tonight, Brian

Laurie, you have done the same thing as Mike did a while ago. You assume that because I don't claim genius or expertise that I think I'm useless. Must be a Kantian thing. Anyway, I thought it was Socrates who said that 'I know that I know very little' and that was supposedly something worthy. I claim that tradition!

Other Comments by Brian English

163. Comment #231297 by Bonzai on August 16, 2008 at 5:35 am

8theist,

I see, that was funny.

Other Comments by Bonzai

164. Comment #231299 by 8teist on August 16, 2008 at 5:37 am

I guess you had to be there ;)

Other Comments by 8teist

165. Comment #231300 by Brian English on August 16, 2008 at 5:37 am

Bonzai, yes, I guess I am doing a psy major not that we term it thus here. That book looks interesting. Probably better than my two statistics books. However, today I bought the only material item I've coveted for the last 20 years. It was quite expensive, and to be granted such a luxury I have agreed to call the item my next 2 birthday and Christmas presents and not buy books for a year.

I'm happy, yet sad. Such is life. :)

Other Comments by Brian English

166. Comment #231301 by Bonzai on August 16, 2008 at 5:39 am

Brian,

if you want the book pm me. :)

Other Comments by Bonzai

167. Comment #231302 by Brian English on August 16, 2008 at 5:41 am

8teist, if those are finches, then I have no idea what a finch looks like. :)

Other Comments by Brian English

168. Comment #231303 by bugaboo on August 16, 2008 at 5:43 am

8teist

From the same website-

Enola Homosexual Drops A-Bomb on Japan!

Other Comments by bugaboo

169. Comment #231304 by 8teist on August 16, 2008 at 5:44 am

They look like this.

<--------.

Other Comments by 8teist

170. Comment #231305 by 8teist on August 16, 2008 at 5:45 am

Hehe........:o

Other Comments by 8teist

171. Comment #231306 by Laurie Fraser on August 16, 2008 at 5:45 am

Brian - sorry, mate; you are obviously on top of your game. Ah, Socrates, now there's a lovely little thinker!

8teist - those things are "finches" from some hallucinogenic hell! (My grand-daughter thinks they're great, though.)

Other Comments by Laurie Fraser

172. Comment #231307 by bugaboo on August 16, 2008 at 5:46 am

Does anyone know why i cant see any avatars?

Edit: Ah! they're back

Other Comments by bugaboo

173. Comment #231308 by Brian English on August 16, 2008 at 5:47 am

Some would say they look like this:

others would say like this:

Other Comments by Brian English

174. Comment #231309 by Laurie Fraser on August 16, 2008 at 5:49 am

Cause you're blind, bugaboo. :) Um, seriously, don't know - no problem at my end. (Besides, at the moment you've got a choice of hallucinogenic finches, some geezer in a bird suit and me looking like a Chaucerian poker has just been inserted.)

Other Comments by Laurie Fraser

175. Comment #231310 by 8teist on August 16, 2008 at 5:49 am

Laurie, get your granddaughter Monsters Inc. from the video store,in the extras on the dvd look for "for the birds".
Its the funniest short I`ve ever seen.

Other Comments by 8teist

176. Comment #231311 by Brian English on August 16, 2008 at 5:51 am

Laurie, don't be sorry. I would think that reading my meanderings would drive any sane person to distraction. I use the net as a sort of catch up place/discussion place/work out stuff place. I probably am more erratic than I imagine. :P

Other Comments by Brian English

177. Comment #231313 by Bonzai on August 16, 2008 at 5:52 am

Laurie, get your granddaughter Monsters Inc. from the video store,in the extras on the dvd look for "for the birds".
Its the funniest short I`ve ever seen.

http://www.youtube.com/watch?v=1-uXEN_eRwo

Other Comments by Bonzai

178. Comment #231314 by Laurie Fraser on August 16, 2008 at 5:53 am

Will do, 8. Nice photos, Brian. We have a very famous horse trainer in Australia called Homosexual Waterhouse.

how can this be? Here we were, happily discussing Kant and Hume (oh frabjous joy), and suddenly we're making stupid jokes about the g word. I blame 8teist. Bastard. Kiwi. Hey mate, your girl's on in a minute.

Other Comments by Laurie Fraser

179. Comment #231315 by Brian English on August 16, 2008 at 5:56 am

Those birds were sparrows, not finches.

Other Comments by Brian English

180. Comment #231316 by Brian English on August 16, 2008 at 5:57 am

(oh frabjous joy),

What does frabjous means? The only time I've see that word before was as part of Richard Morgans email address....

Other Comments by Brian English

181. Comment #231317 by 8teist on August 16, 2008 at 5:58 am

All them birds look the same to me :o

Other Comments by 8teist

182. Comment #231318 by bugaboo on August 16, 2008 at 5:58 am

laurie

Trying to move the discussion over to Nietzsche The homosexual scie...

i'll get my coat

Brian

beware the Jaberwock...

Other Comments by bugaboo

183. Comment #231320 by Laurie Fraser on August 16, 2008 at 5:59 am

I don't know, Brian - it was an expression Horace Rumpole was wont to use. Sounds good, so I'll use it meself.

Edit:
frabjous |ˈfrabjəs|
adjective humorous
delightful; joyous : “Oh frabjous day!” she giggled.

Other Comments by Laurie Fraser

184. Comment #231321 by Brian English on August 16, 2008 at 6:00 am

I've not read any Nietzsche. Apparently Christians think he's the devil, but philosophers don't. Why is that?

Other Comments by Brian English

185. Comment #231322 by Brian English on August 16, 2008 at 6:01 am

frabjous

A combination of Fair, fabulous and joyous.
Usually defined as wonderful.

I thought it wasn't a common word so never looked it up before...

Other Comments by Brian English

186. Comment #231323 by Brian English on August 16, 2008 at 6:03 am

Beware the Jabberwocky? Well,I haven't watched any python for a while (although I read it may have been Lewis Carrol's idea).

Other Comments by Brian English

187. Comment #231325 by 8teist on August 16, 2008 at 6:03 am

http://www.youtube.com/watch?v=1-uXEN_eRwo

I forgot I got the intertube thingy

now I got some rugby to watch back in 40

Other Comments by 8teist

188. Comment #231327 by bugaboo on August 16, 2008 at 6:06 am

"And, has thou slain the Jabberwock?
Come to my arms, my beamish boy!
O frabjous day! Callooh! Callay!'
He chortled in his joy.

Carroll

Its now time to go blow the froth off of a few cold ones

bye all

Other Comments by bugaboo

189. Comment #231328 by decius on August 16, 2008 at 6:07 am

Comment #231277 by Laurie Fraser

it's arguable that it was Kant who was the genuine father of modern science.

I dispute that.

Philosophia Naturalis had neatly separated from philosophy back in the XVI century. The appointment of the by-now obscure Jacopo Zabarella as chair of Natural Philosophy in Padua demonstrates it.
Attempts at developing a scientific method, independent from the philosophical methods of enquiry, date back to antiquity and were revamped in the early Middle Ages.
The evolution of Philosophia Naturalis into modern science has been independently unfolding through a trial-and-error process, which took little notice of the abstractions and framing coming from other quarters.
While philosophy of science is a great tool for interpreting and understanding the foundations of science and its implications at large, it cannot honestly claim its paternity. Saying otherwise is a bit like claiming that Newton is the father of gravity, implying authorship of that very law of nature.

Ultimately, science cannot be any different from what it is, as there are no competing effective scientific methods to choose from. People who worked hardly in the field are the fathers, or - more precisely - the step-fathers of science, no one else.

Other Comments by decius

190. Comment #231330 by Laurie Fraser on August 16, 2008 at 6:11 am

Nietzsche - hated by christians, cause he pointed out the elephant in the room. The idea of intentionality - a far more astute notion than the christian idea of a god who creates a being whose will is a simple "bestial" derivation of natural desire. See, there's that id popping up again, Brian.

Other Comments by Laurie Fraser

191. Comment #231332 by Brian English on August 16, 2008 at 6:13 am

Decius, I don't think anyone can claim to be the father of something that was so inter-temporal and collaborative. Perhaps the greats could claim to be ushers of the truth or something. The ancients, Galileo, Newton, Einstein, (and so many who deserve mention but have been forgotten) etc are all just candle bearers or guides of the slow, refining method of approximating what may be the truth that we can understand...science.

Other Comments by Brian English

192. Comment #231335 by Brian English on August 16, 2008 at 6:15 am

The id popping up again Laurie? Well, the mind keeps popping up again, doesn't mean it's a part of our ontological inventory does it?

Other Comments by Brian English

193. Comment #231337 by Bonzai on August 16, 2008 at 6:19 am

189. Comment #231328 by decius

Well said.

Other Comments by Bonzai

194. Comment #231338 by Laurie Fraser on August 16, 2008 at 6:19 am

Bloody hell, Decius, I knew somebody would pick me up on my trite assertion. OK, your points are granted, of course. In my defence, I'd simply claim that Kant provided a way forward for science to justify its programme, in that the business of practical science, which was of course proceeding apace, could provide at last an epistemological underpinning. I don't really think we need to debate the philosophy/science schism; we've been around the world on that one on RDnet already.

Edit: besides, I'm really tired. (boo hoo asks for sympathy)

Other Comments by Laurie Fraser

195. Comment #231339 by Brian English on August 16, 2008 at 6:23 am

Bonzai, how did I know you'd agree with Decius' statment? I agree with it too. I'm sort of stuck in an untenable position. I think science has precedence of all knowledge (if a logical contradiction is demonstrated by empirical methods I'll go with the empirical methods e.g. Kant's every effect has a cause has been shown wrong by virtual particles having no cause.), but philosophy can justify science's claim and correct it when it staggers into the purely speculative (M theory?). But the trouble is, to me anyway, most philosophers don't understand the science, at the cutting edge at least. In Kant's, Liebnitz' or Hume's time, the philosophers could know the state of the art.

Other Comments by Brian English

196. Comment #231341 by decius on August 16, 2008 at 6:28 am

Comment #231337 by Bonzai

Thank you.

Other Comments by decius

197. Comment #231342 by decius on August 16, 2008 at 6:30 am

Comment #231338 by Laurie Fraser

I agree.

And you have all my sympathy and friendship, of course. :)

Other Comments by decius

198. Comment #231344 by Bonzai on August 16, 2008 at 6:33 am

but philosophy can justify science's claim and correct it when it staggers into the purely speculative (M theory?).

I don't think science needs justification from philosophy, science justifies itself on its own terms.

I am also sure that many scientists would be able to critically discuss their own subjects when it strays into speculations without being told by armchair philosophers. IMO if a scientific field has rooms for the philosospher at all, it indicates that either the field (cognitive science, say) is not yet well develop into a mature science or there are some serious problems (foundation of QM e.g)

Other Comments by Bonzai

199. Comment #231345 by Laurie Fraser on August 16, 2008 at 6:33 am

Well chaps, I'm going to hit the sack. This has been a most stimulating discussion. Please have a look at my blog on "Terror" : http://www.churchofrationalism.blogspot.com/ - I'd be interested in your comments; it's the first time I've ever written about the subject-matter. Thanks, Brian; Decius; 8; Bonzai; bugaboo. Thanks, isthatclear, for nuthin'.

Other Comments by Laurie Fraser

200. Comment #231346 by Brian English on August 16, 2008 at 6:33 am